This invention relates to a roller conveyor with pivoting rollers for transporting goods and with a belt arranged under the rollers for driving the rollers, whereby the belt is aligned substantially vertical.
Such roller conveyors with driven roller tracks are already known. Basically these drives are constituted either by chains or belts. The advantage of belts over chains is that a belt drive is comparatively low in noise and can reach high speeds. With a belt drive there is a distinction made between a drive using flat belts and round belts. Examples of flat belts also are toothed belts. By comparison, V-belts come under the category of round belts. The advantage to the flat belt is that large forces can be transferred. But due to its horizontal alignment beneath the rollers the flat belt cannot be bent to the sides and accordingly is suited only for drive in straight sections. Cross ties, such as for example Kevlar threads or wire pulls or also quite generally particularly hard-wearing fabric, are integrated into flat belts, so that roller conveyors with lengths of approximately 20 m to 30 m can be driven with the flat belt with its substantially rectangular profile. On the contrary, round belts can also be guided to the sides and can thus also be used for driving in curves, for example. Such round belts are generally suitable only for roller conveyors up to 10 m.
The object of the invention is to provide a roller conveyor of the type initially outlined, which can also be driven in curved areas with a belt particularly capable of bearing.
According to the present invention in the case of a roller conveyor with pivoting rollers for transporting goods and with a belt arranged over the rollers for driving the rollers, whereby the belt is aligned substantially vertical, arranged on the upper edge of the belt, with in contact the rollers, is a continuous profile element without interruptions and the profile element is designed to be wider than the belt and projects over the latter from both sides. It can be a lengthways extending belt, in particular with a substantially rectangular profile, which is adequately provided with cross ties, such as Kevlar threads or wires, and in this way can withstand particularly high tensile forces and can be designed correspondingly long. Through vertical alignment of the belt lateral movement is also feasible, and the belt can follow the curves and arcs of the roller conveyor. With such alignment it is a further advantage if less contamination can accumulate on the relatively narrow upper edge of the profile element and thus also less dirt is transferred to the rollers and the goods to be conveyed. Maintenance expenses are also accordingly lower. This particularly so, as the upper width of the profile element is less than the otherwise standard width of the belt or, in the present case, the width of the profile element is less than the height of the vertically positioned belt. The profile element is designed to be continuous over the entire length of the belt, so that there is constant contact being made by the profile element with the rollers driven by the belt and the profile element. The profile element is designed wider than the belt and projects over the latter on both sides, guaranteeing good power transfer. At the same time the profile element is preferably designed symmetrical, in particular symmetrical to the vertical axis of the belt.
The profile element preferably has polyurethane or consists of polyurethane or another material, which has a comparatively high friction coefficient and additionally can be moved laterally. The profile element is preferably designed substantially T-shaped and in one piece. This means that the central leg of the T is provided with a central slot, can be set on the belt and can be connected thereto, and the upper transverse beam of the T, with a broader face compared to the upper edge of the belt, can come to bear on the roller. Particularly preferably the profile element is designed as a 2-point bearing. When this is designed as a T-profile both outer ends are arched upwards, resulting overall in cleated bending or arching. Both outer areas then form the 2-point bearing.
In another particularly preferred embodiment the profile element is preferably one piece and is designed arched, resulting in a heaped or convex arch. Here the central part of the profile element, in contact with the rollers, is higher than the outer areas of the profile element which project laterally over the belt. The profile element is designed preferably as a segment of a circle and in a further preferred embodiment has a recess, which beneficially has a longitudinal form and is designed to be at a constant distance to the upper sealing surface of the profile element. The result of this recess is that the profile element can subside resiliently and the rollers can loop in the longitudinal direction of the belt, so that the profile element not only comes into contact with the roller in contact at one point, but over a certain length, viewed in the direction of traction.
In cross-section the belt is designed substantially rectangular. Such belts are particularly simple to manufacture. In another preferred further development of the invention the belt and the profile element are designed monobloc.
The belt is preferably arranged in the vicinity of the inner curve of the roller conveyor and lies in this region on the rollers. The roller conveyor preferably has crowned drive and guide elements, by which the vertically aligned belt is guided to prevent it from twisting. It is also beneficial, t provide ball bearings arranged laterally on the vertically aligned belt. This results in particularly good curving. The ball bearings are preferably arranged in curved regions in the external radius. In a further development the ball bearings are arranged at certain distances alternating on both sides of the belt.
A further aspect of the invention is the preparation of a belt for the roller conveyor according to the present invention with the above described preferred configurations.